As is known, many commercial and industrial activities require a fixed number of articles that are generally fed randomly and are loosely ordered and then automatically sorted so that they can thereafter be handled more easily in an automatic or semi automatic way.
The machines predisposed to this operation are known as “singulators”.
The areas of use of the singulator are varied, and are cited by way of non-limiting example to the field of sorting and delivering mail, the dispatching and parcel distribution sector, etc.
There are several equipment on the market today suitable for the performance of the above-mentioned task.
A first type of this machine comprises, in the main structure thereof destined for singulating operations, the use of a first converger station constituted by a central high-friction conveyor belt flanked on both sides by two respective roller planes having inclined axes with respect to the advancement direction of the articles.
The roller planes impart, on the articles resting thereon, an advancement motion and lateral translation towards the high friction central belt bearing the majority of articles on the central belt itself.
A diverger station is located after the converger station, which diverger station is also a high-friction central belt which follows on from the central belt of the converger station and is destined to receive the articles that have been brought to the central zone of the device.
Two roller planes are flanked to the central belt, having rollers with inclined axes destined to impart on the articles entirely resting thereon an advancement motion and a corresponding lateral movement which distance them from the high-friction central belt. In particular, an article that might be at least partially resting on the central belt would be transported thereby and would not be affected by the lateral thrust of the corresponding roller plane; vice versa, a product resting exclusively on the roller plane is distanced from the central belt.
Appropriate conveyor belts or recirculating belts are present at the flanks of the diverger station, which belts are destined to receive the products that have been distanced from the diverging roller planes and return them to the inlet of the machine and in particular to the inlet of the converger station so that they can be newly processed.
Conversely, the singulated products that are on the high friction central belt proceed towards the further process stations.
In this way the products are singulated at the central zone of the machine, while all the articles which, in particular due to being superposed in a transversal direction to the transport direction, should they not reach the central zone, are advantageously recirculated via the diverger station, and via the recirculating belts are returned in inlet to the machine and thus re-processed.
U.S. Pat. No. 5,701,989 describes, with particular reference to FIG. 13, a device similar to the one described above and used in commerce.
The main difference is linked to the absence of a conveyor belt at the convergence zone (in other words there are only two roller planes converging towards the central advancement axis) and to the presence of a diverger station constituted by a plurality of additional conveyor belts with the aim of removing articles that are not singulated in such a way to return them into the singulating cycle.
A second type of known devices suitable for singulating products is constituted by a complex apparatus in which all articles entering the device are suitably scanned by, for example, suitable cameras which can provide the detected information to a control unit which reconstructs the distribution of the articles along the advancement pathway thereof.
In particular, a movement plane is present, constituted by an array of individual conveyor belts, all independently movable.
In other words, the movement plane consists of a fixed number of rows and columns defined by a plurality of individual conveyor belts which are commanded by the control unit via respective motors.
As the control unit has the position of the single articles in its memory, and is monitoring the movements, it commands the conveyor belts with differentiated velocities, such as to be able to suitably orientate the articles by rotating them, and also being able to distance them in the longitudinal direction by differentiating the advancement velocities of the belts on which the articles are resting.
When leaving the plane, the various articles will be orientated in an orderly manner and will be sufficiently spaced along their respective advancement lines.
In this way it is possible to operate downstream of the movement plane of the articles, as they are already pre-ordered, and perform thereon a final singulation.
The above-mentioned machine is at least partially described in some patent publications, for example, in patents EP 1556297 and U.S. 2003/141165.
The singulators briefly described above, while admirably fulfilling the tasks they are designed for, are not free from limitations and/or operational problems.
For example, the singulator involving exhibiting converger station, the diverger station and the recirculating belt is extremely large both longitudinally and transversally.
In fact, the operating principle requires bearing all the products on the central singulating conveyor belt, and leads to the requirement to have determined lengths in the transport direction so as to ensure adequate filling of the high friction central belt.
Further, the need to be able to recircule products that have not been singulated requires the presence of two further recirculating belts positioned at the flanks of the machine, which obviously increases the dimensions of the apparatus in that direction.
The above will generally involve the need to have large volumes/dimensions in order to install the singulators in question, resulting in increases in costs of both construction of the device and the management of the machine itself.
Conversely, as the device exhibits the multiplicity of conveyor belts that are independently movable, it is much more compact, but at the same time, extremely complex in terms of construction and operation management. Indeed, it is necessary to predispose a control unit and cameras to monitor suitable movement of articles, as well as a control algorithm that can enable efficient and individual operation in a controlled manner on each of the conveyor belts.
Further, each of the conveyor belts is fitted with a respective activation and a respective motor, which clearly increase the constructional and maintenance costs, while at the same time reducing the reliability of the singulator (considering the high number of electrical and mechanical parts that make it up).